Expansible shaft



inited States l arent EXPANSIBLE SHAFT Charles Robert Tidland, RO. Box 695, Camas, Wash., assignor of lone-half to Arthur T. Williams Filed Aug. 12, 1957, Ser. No. 677,585

2 Claims. (Cl. 242-72) This invention relates in general to winder shafts on which rolls of paper, or other sheet material, may be wound, and, more specifically, relates to an expansible shaft on which -a roll of paper may be wound while the shaft is in expanded position, permitting the shaft subsequently to be withdrawn from the completed roll when the shaft is contracted; or a shaft which similarly may be inserted in the core of a roll in contracted position and then expanded to 'hold the roll firmly for the unwinding of the roll.

An object of the present invention is to provide an improved expansible shaft on which a roll of paper can be wound directly when the shaft is in expanded position, without any core of cardboard or the like being used for the roll, and from which wound roll the shaft can then be easily extracted, even though no core of cardboard or other material has been used forthe paper.

Another object of the invention is to provide an expansible shaft which can be made in any desired size, and which, when made in the proper size for large heavy rolls of paper, will have ample strength to sustain the weight of such heavy rolls, and which will not be subjected to any appreciable deflection in use regardless of the load imposed upon the shaft or the speed at which the winding (or unwinding) takes place.

An additional object of the present invention is to provide a simplified and improved expansible Winder shaft, the outside surface of which will comprise smooth, strong, cylindrical sections, whether the shaft is in expanded or contracted position.

A vfurther object of the invention is to provide an improved pneumaticallyexpansible shaft in which a single expansible inner tube, comparatively of only moderate size, will provide the desired expansion of the shaft when a moderate amount of air under pressure is delivered to such inner tube, and which will then hold the shaft in expanded position until the air is permitted to escape from the inner tube.

When an expansible shaft of the type above indicated is expanded as a result of the inflation of an inner tube, it is important that the outer surface members or gripping elements should return immediately and completely to their normal or maximum contracted position whenever the inner tube is suiciently deated, so that no difficulty or delay will be experienced in removing the shaft from the completed roll when this is desired. Should the outer surface members have any tendency to remain in the expanded or partly expanded position, particularly in the case of shafts used for very large rolls of paper, after the inner tube has been deflated, certain inconvenience and delay arises in the removal of the shaft from the roll core. An important object of the present invention accordingly is to provide special spring means which will automatically move the outer surface members radially inwardly to their maximum contracted position whenever Vthe inner tube is sufficiently deated.

- Fatenteol Aug. 23, 1960 bers of the shaft that the tension of the spring means can be adjusted, whenever necessary, so as to insure complete and quick return of the surface members to their retracted position whenever the inner tube is deflated for this purpose.

These objects and other incidental advantages are attained by constructing the improved expansible shaft substantiallyy as explained in the followingbrief description with reference to the drawings.

In the drawings:

-Figure -1 is a fragmentary sectional eleva-tion of the expansible shaft taken longitudinally on the line indicated at 1--1 in Figure 2, the shaft being shown in fully expanded position;

Figure 2 is a cross section taken on the line indicated at 2 2 in Figure 1;

Figure 3 is a corresponding cross section taken on the line indicated at 3-3 in -Figure 1; and

Figure 4 is a cross section similar to Figure 2 but showing the shaft in fully contracted position.

Referring first to Figure l, the main body of the shaft consists of -a cylindrical metal tube 10 the length of which is equal at least to the width of the paper, or other material, with which the shaft is to be employed. At its ends this tubular body 10 is rigidly secured to sui-table journal members (not shown) at least one of which is hollow.

The body member 10 is formed vw'th a plurality of identical, equally spaced series or groups of radial holes or channels 1-1, the radial channels in each group being located in a plane perpendicular to the axis of the body member 1@ and the corresponding radial channels in the various groups being aligned longitudinally along the body member 1d. A raised portion or boss 12 surrounds each channel 11. In the particular form of the expansible shaft illustrated in the accompanying drawings there are iive such channels in each of the separate groups and the channels in each group consequently are arranged at 72 with respect to each other.

A plurality of identical longitudinal inner segments 13 (there being five such longitudinal segments in the device illustrated), are located inside the tubular main body rnember 10. The length of these inner longitudinal segments is almost equal to the length of the main body member 10. Each inner longitudinal segment 13 carries a row of stub shafts 14, the longitudinal spacing of which corresponds to the longitudinal spacing of the groups of channels 11 in the main body member 10, so that the stub shafts 14 from each longitudinal segment 13 extend through and are slidably supported in one longitudinal row of channels l1-1.

w A corresponding number of outer cylindrical segments 15 (thus there being five such outer cylindrical segments in the device illustrated) are mounted on .the outer ends of the stub shafts 14 of the corresponding inner. longitudinal segments 13 and have substantially the same lengtfh as the inner segments `13. These outer cylindrical segments 15 are reinforced by transversely extending inside ribs `16, the longitudinal spacing of which correspends to the longitudinal spacing of the groups of channels 11 and of the stub shafts 14. Each inside transverse rib 16 has a central boss 17 formed with a recess or socket in which the outer end of the corresponding stub shaft 14 is secured. Thus each outer cylindrical,

longitudinal segment 13.

. An inner tube 18, .of -rubber or similar resilient ilexible material, extends throughout the main body member inside the inner longitudinal segments 13 and bears against these segments 13 at all times. One end (not shown) of this inner tube -is sealed, and the other end (not shown) is connected to a tube (not shown) extending through a hollow journal end of the shaft, and

such tube is provided at its outer end with a suitable valve, such for example as is used on auto tires, whereby ai-r pressure can be delivered into said inner tube when the shaft is to be expanded and through which the air can -be exhausted from said Iinner tube when the shaft is to be contracted. Such arrangement for iniiating and deilating an inner tube in an expansible shaft is well `known and need not be described here, and is shown, for example, -in U.S. Patent No. 2,537,492 issued under date of January 9, 1951.

The arcuate width of the outside surfaces of each of the identical outer cylindrical segments 15 is such that, when the expansible shaft is in the fully contracted position illust-rated in Figure 4, the outer segments will form a complete cylindrical outer surface. Thus in the form of the device illustrated in the drawings the arcuate width of each of the outer segments is 72.

In order to insure that the outer cylindrical segments 15 will always return immediately to the fully contracted position, as illustrated in Figure 4, whenever lthe inner tube 18 is suiciently deilated to enable 4them to do so, and similarly to insure that the longitudinal inner segments 13 will maintain contact with and 4bear against the surface of the inner tube 1E constantly until the shaft returns to fully contracted position, special coil springs 19 are provide-d and are connected withthe outer cylinder segments 15, as shown in Figure 3 and as now -to be described.-

Each of the outer cylindrical segments 15 is provided with a plurality of apertures for receiving spring-mounting screws Z0 (Figures 1 and 3). The apertures for these screws 20 are located along the center longitudinal line of each segment 15 and thus are in alignment with the sockets for the stub shafts 14 and the bosses 17. A boss 21 surrounds each aperture for the screws 211 in each outer cylindrical segment 15, the bosses being welded to the inside surface of the cylindrical segments 15 or formed integrally with the cylindrical segments. These bosses reinforce the cylindrical segments around the screw apertures, and the outer ends of the apertures are beveled, as shown in Figure 3 to correspond to and to accommodate the beveled heads 2G of the screws 20 so that the screw heads 20' will be countersunk or llush with the outer surfaces of the segments 15. The apertures and bossesp21 are so arranged that they will maintain the screws 20 positioned radially with respect to the axis of the shaft, as apparent from Figure 3. The screws 20 are rotatable in their apertures and bosses, and the screw heads are provided with the usual slot (or other desired type of screwdriver recess) to enable the screws 20 to be turned by a suitable screwdriver for reasons presently apparent. Preferably the screws 20 are so arranged that each screw 20 is positioned between each pair of stub shafts 14 along each outer cylindrical segment 15 as shown in Figure l.

A wing nut 22 is mounted on each screw 20. The sides or wings on these nuts are provided with apertures to which the ends of adjacent coil springs 19 are secured, the coil springs 19 being under tension. It will be obvious from Figure 3 that, since all the springs in each group are under tension, the springs in each group will combine in constantly exerting an inward pull on the outer cylindrical segments 15, and this pull will be exerted inwardly in a radial direction. Thus these series of groups of springs operate to return the cylindrical segments 15 to retracted position Whenever the release of the air pressure in the inner tube 18 makes this possible.

By turning the screws '20, the wing nuts 22 on the screws may be adjusted either outwardly or inwardly.

Consequently, as apparent from Figure 3, the tension of the springs 19 for any given position of the outer cylindrical segments 15 can be increased by adjusting the wing nuts outwardly and similarly the tension can be reduced by adjusting the wing nuts in the opposite direction, or inwardly, on the screws 20. Accordingly in this irnproved shaft the tension of the springs in each group along the shaft can be adjusted whenever this is desired or whenever this becomes necessary and all that is required is the turning of the screws 28 in each group by means of a suitable screwdriver. Thus even if the springs, as a result of long service, lose some of their tension, this condition is easily remedied by tightening the springs by adjusting the wing nuts in an outward direction, which operation is easily performed and does not require any dismantling of the shaft. This provision for spring adjustment is an important and novel feature of this improved shaft.

lt is to be understood of course that the expansible shaft can be made with more or with less outer and inner longitudinal segments than the five shown in the drawings. Also, other minor modifications would be possible without departing from the principle of the invention while retaining the feature of the readily adjustable spring means by which the shaft is returned to contracted position.

I claim:

l. In an expansible shaft having a main tubular body, a plurality of inner identical longitudinal segments located within said tubular body, and an inner tube of flexible and resilient material located within said tubular body on the inside of said longitudinal segments and adapted to be inated and deflated when desired, spaced longitudinally-aligned stub shafts secured to and extending radially outwardly from each of said inner longitudinal segments, channels in said tubular body for said stub shafts permitting radial movement of said lstub shafts and therewith said inner longitudinal segments in said tubular body, the length of said stub shafts being greater than the thickness of the wall of said tubular body, a plurality of outer, identical, cylindrical segments on the outside of said tubular body corresponding to the number of said inner longitudinal segments, said outer cylindrical segments mounted on the outer ends of said stub shafts, screw-threaded members rotatably mounted in said outer cylindrical segments and extending inwardly therefrom, a nut mounted on each member, and coil springs having their ends attached respectively to the nuts on the correspending members in adjacent outer cylindrical segments and maintained under tension so as to exert a combined force to pull said outer cylindrical segments inwardly, whereby said coil springs will cause said shaft to be contracted by the inward movement of said outer cylindrical segments whenever said inner tube is deflated, and whereby the adjustment of said nuts rulting from the turning of said screw-threaded members will enable the tension of said springs to be adjusted as desired.

2. In an expansible shaft of the character described having a main tubular body, a plurality of inner identical longitudinal segments located within said tubular body, and an inner tube of flexible and resilient material located within said tubular body on the inside of said longitudinal segments and adapted to be inflated and deilated when desired, spaced longitudinally-aligned stub shafts secured to and extending radially outwardly from each of said inner longitudinal segments, channels in said tubular body for said stub shafts permitting radial movement of said stub shafts and therewith said inner longitudinal segments in said tubular body, the length of said stub shafts being greater than the thickness of the wall of said tubular body, a plurality of outer, identical, cylindrical segments on the outside of said tubular body corresponding to the number of said inner longitudinal segments, said outer cylindrical segments mounted on the outer ends of said stub shafts, the length of said outer cylindrical segments 5 being substantially equal to the length of said tubular body, transverse ribs on the under side of said outer cylindrical segments, the outer ends of said stub shafts secured to the centers of said ribs respectively, screw threaded members rotatably mounted in said outer cylindrical segments and extending radially inwardly therefrom, a wing nut mounted on each member, and coil springs having their ends attached respectively to the wing nuts on the corresponding members in adjacent outer cylindrical segments and maintained under tension so as 10 to exert a combined force to pull said outer cylindrical segments inwardly, whereby said coil springs will cause said shaft to be contracted by the inward movement of said outer cylindrical segments whenever said inner tube is deflated, and whereby the adjustment of said Wing nuts obtained by the turning of said screw threaded members Will enable the tension of said `springs to be adjusted as desired.

References Cited in the le of this patent UNITED STATES PATENTS 2,529,185 Proctor Nov. 7, 195o 2,537,492 Tidland Jan. 9, 1951 2,727,700 Van Colle et al. Dec. 20, 1955 FOREIGN PATENTS 397,659 Great Britain Aug. 31, 1933 

